public class Example4_5 {
  public static void main(String args[]) {
    Rect ractangle =new Rect();
    ractangle.width=109.87;
    ractangle.height =25.18;
    double area =ractangle.getArea();
    System.out.println("矩形的面积:"+area);
    Lader lader=new Lader();
    lader.above =10.798;
    lader.bottom=156.65;
    lader.height=18.12;
    area =lader.getArea();
    System.out.println("梯形的面积:"+area);
  }
}
